Oxidation of certain 3-substituted tetrahydrothiophenes with potassium peroxymonosulfate to the corresponding sulfoxides proceeds with a high degree of stereoselectivity. In the sulfoxide product, the isomer in which the 3-substituent and the sulfoxide oxygen are trans predominates over the corresponding cis-isomer by a factor of at least 10:1. The 3-substituent is a leaving group, such as I, Br or a sulfonyloxy group. The products of the oxidation process are intermediates to penem antibiotics known from U.S. Patent No. 4,619,924.  
                            某些 3-取代的
四氢噻吩与过一
硫酸钾发生氧化反应,生成相应的亚砜,具有很高的立体选择性。在亚砜产物中,3-取代基和亚砜氧为反式的异构体比相应的顺式异构体占优势,其比例至少为 10:1。3 取代基为离去基团,如 I、Br 或磺酰氧基团。氧化过程的产物是美国专利第 4,619,924 号中已知的青霉烯抗生素的中间体。